Radioactive iodine therapy for thyroid cancer
Radioactive iodine therapy is a treatment that uses radiation to treat thyroid cancer.
What is radioactive iodine therapy?
- Radioactive iodine therapy is a type of internal radiotherapy. The radioactive iodine, sometimes called radioactive-iodine 131, is usually given as a capsule.
- Not all patients need radioactive iodine therapy. You will be referred to a specialist centre for this treatment if you need it.
- This therapy can destroy tiny amounts of normal thyroid tissue or any cancer cells left behind after surgery. It is usually given after surgery for papillary or follicular thyroid cancer. You may have to wait several weeks to recover after surgery before having this treatment.
Preparing for radioactive iodine therapy
You will need a high level of thyroid-stimulating hormone (TSH) in your bloodstream for the treatment to be a success. This is done by giving an injection of TSH before treatment. The hormone activates thyroid cells and encourages them to absorb the radioactive iodine.
Taking recombinant TSH: You will continue on your hormone therapy and be given recombinant human TSH (rhTSH). The drug is given over 2 days before the iodine capsule is taken. It boosts the level of TSH in your body to make sure the radioactive iodine therapy works.
Your doctor or nurse may advise you to limit the amount of iodine in your diet for 2 weeks beforehand. A low-iodine diet may help your body to take up the radioactive iodine more effectively.
Iodine is mainly found in seafood, eggs and dairy products, such as milk, yoghurt and cheese.
Do not stop eating these foods, just reduce the amounts. Your doctor, nurse, or dietitian can give you more advice.
Use a reliable method of contraception before you start treatment – it’s important that you or your partner do not become pregnant during treatment and for a few months afterwards. Ask your doctor about this. Tell your doctor if there’s a chance you might be pregnant. Radioiodine treatment can harm the baby and so isn’t suitable if you are pregnant or might be pregnant.
If you are breastfeeding or expressing milk, you must stop 6-8 weeks before your treatment. It is best if your child is weaned before treatment or if treatment is postponed until your baby is weaned. It is not safe to start breastfeeding again after your treatment, but future pregnancies and breastfeeding will not be affected.
Getting radioactive iodine therapy
Usually you will be given a small capsule. The radioiodine goes into your bloodstream and travels to thyroid cells in your body. The thyroid cells absorb the radioiodine and it kills them.
Harm to other cells in your body is minimal as they do not absorb the radioiodine. The treatment can be repeated if thyroid cells are still present.
This treatment does not hurt.
After radioactive iodine therapy
The therapy makes you radioactive for a few days. As a result, you will need to be nursed in isolation, usually for up to 3 days. You will stay in your room until the radioactivity has reduced to a safe level. It is gradually lost from your body in your urine, stools (poo), blood, saliva and sweat. Drinking lots of fluids will help get rid of the radiation quicker.
There is a chance that hospital staff and your relatives and friends might be exposed to the radiation. Because of this, certain safety precautions are taken while the radioiodine is still in your body. It is important to check the rules about visitors in the hospital you are attending. For example, some hospitals may not let visitors into your room at all, while others may allow visitors into your room after 24 hours.
If visitors are allowed after 24 hours, strict rules will apply. Visits will be limited in time and visitors will have to stay a certain distance from you.
Children under 14 and pregnant women will not be allowed to visit you.
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